Eupsophus altor, Nuñez & Rabanal & Formas, 2012
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publication ID |
https://doi.org/ 10.11646/zootaxa.3305.1.3 |
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persistent identifier |
https://treatment.plazi.org/id/8A4D051E-6B4F-FFED-B2EC-50A37B18567E |
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treatment provided by |
Felipe |
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scientific name |
Eupsophus altor |
| status |
sp. nov. |
Eupsophus altor View in CoL sp. nov. Nuñez, Rabanal & Formas ( Fig. 5 View FIGURE 5 )
Oncol’s ground frog (English) Rana de hojarasca de Oncol (Spanish)
Type Material. Holotype. IZUA 3607 View Materials , adult male collected by Felipe Rabanal and José Nuñez on 11 June 2008 at the Cerro Oncol (39º41’S; 73º19’W, 650 m a.s.l.), Coastal range, Valdivia Province, 40 km W (by road) of Valdivia city, Chile ( Fig. 1 View FIGURE 1 ) GoogleMaps . Paratypes. IZUA 3608–3620 View Materials , collected at the type locality, same data as holotype GoogleMaps .
Diagnosis. The species is assigned to the genus Eupsophus because it has the following osteological cranial pattern (cervical cotylar arrangement type II; palatal shelf of premaxilla relatively deep; palatal shelf of maxilla of moderate width; pterygoid process moderately large; nasals small, widely separated medially; nasals in broad contact with maxillae, not in contact with pterygoids; epiotic eminences prominent; zygomatic ramus of squamosal of moderate length, widely separated from maxilla; otic ramus of squamosal as long as zygomatic ramus, expanded medially into small otic plate; squamosal-maxillary angle 50–55°; palatines broad, widely separated medially, bearing odontoid ridges; sphenethmoid entire, extending anteriorly to anterior edge of nasals parasphenoid alae oriented at right angles to anterior ramus of parasphenoid, broadly overlapped laterally by median rami of pterygoid) as has been described by Lynch (1971) and endotrophic tadpoles ( Formas 1985). Eupsophus altor is assigned to the E. roseus Group species by having 2n = 30 chromosomes. Eupsophus altor differs from all species described of the E. roseus group species by having early winter breeding season, terrestrial tadpoles and its advertisement call with spectral elements reaching the 20 kHz, and nine mitochondrial D-loop nucleotide site substitutions from its congeneric species phylogenetically closest.
Description of the holotype. Adult male 36.6 mm in SVL. Head 0.93 times narrow than body; head length 31.7% of SVL; head width 1.2 times broader than long. Snout rounded dorsal view and obtuse in lateral view; loreal region flat, nostrils slightly prominent, oriented laterally; internarial distance 0.31 times the head width, internarial region slightly convex; nostril slightly closer to the anterior border of the eye than the terminus of snout; canthus rostralis marked. Eyes prominent, laterally oriented, 0.44 times the head length; tympanum round, 0.67 times the eye diameter; dorsolateral fold well developed, extending from the posterior corner of eyelid, terminating dorsal to forelimb. Maxillary and premaxillary teeth present; seven prevomerine teeth (4 on the left and 3 on the right), obliquely located between the choanae, small sized (0.26 times internarial distance) and subcircular in shape; tongue rounded, posterior the border slightly notched, attached approximately 66.4% of its length interiorly. Forelimbs slender; dorsal and ventral surfaces smooth. Relative length of the fingers: III>IV>II>I; tips of the fingers rounded and slightly protuberant; subarticular tubercles rounded distributed on fingers as follows: І- ІІ- ІV (1), ІІІ (2); inner palmar tubercle ovoid; outer almost rectangular, as long as the inner; one subarticular tubercle on fingers I–IV; supernumerary palmar tubercles absent; nuptial pads on fingers I–II with tiny spines unpigmented. Hind limbs long and slender (162.8% of SVL); tibiotarsal articulation reaching the posterior border of eye when hind limb is adpressed along the body; toes long and thin, their relative length are: IV>V=III>II>I; a small delicate web between toes III–IV; tips rounded; inner metatarsal tubercle ovoid and developed, external tubercle conical and small, one-fourth of length of inner metatarsal tubercle; subarticular tubercles rounded, distributed on toes as follows: I(1), II(1), III(2), IV(3), V(2). Skin of head, dorsal surface, flanks and limbs smooth; ventral surfaces of limbs smooth; cloacal opening directed posteriorly at ventral level of thighs; cloacal opening unornamentated, covered by a fold of skin; Ventral surface of thighs smooth.
Colour in life. The dorsum is reddish-pink with light gray spots. Extremities with light gray bracelets. The flanks are whitish but with yellow in axillary and inguinal areas. Throat, chest and belly with minute melanophores regularly distributed. The ventral surface is white or creamy ( Fig. 5 View FIGURE 5 ). Upper part of the iris yellowish with black reticulations. Color in preservative (70% ethanol plus NaCl) similar to the live specimens.
Osteology. Neurocranial braincase: The neurocranial braincase is made up of three bones: sphenethmoid, prootics and exoccipitals. It is partially covered by the frontoparietals dorsally and the parasphenoid ventrally ( Fig. 6A View FIGURE 6 ). The sphenethmoid forms the floor, edges of the roof and the anterolateral wall of each side of the braincase. Dorsally occupies a large area (its width is equal to the length of the nasals) between the nasals, frontoparietals and frontoparietal fontanella. Its ventral face overlaps with the inner half of the neopalatines, vomers and anterior end of the cultriform process of the parasphenoid. The prootics are fused with the exoccipitals, forming the posterior region of the braincase and the otic capsules. The exoccipital, which are covered ventrally by the parasphenoid forming the posteromedial walls of the otic capsules, the margin of the foramen magnum, and the occipital condyles.
Dermatocranium: The frontoparietals are paired and their anterior extremes are slightly divergent. The frontoparietals are expanded posteriorly and they overlap the prootics but do not reach the foramen magnum. The frontoparietal fenestra extends forward from the anterior third of the skull. The fontanella is 0.24 times the skull length. The nasals are paired subrectangular bones, transversally oriented and superimposed on the sphenethmoid ( Fig. 6B View FIGURE 6 ). A space separates the nasals from the oblique cartilage of the nasal capsule. The parasphenoid is Tshaped, not fused with the subjacent bones. The cultriform process, which rests on the sphenethmoid, is long not keeled and anteriorly serrated, their tips do not reach the level of the neopalatines. The posteromedial process of the parasphenoid is acuminate and near the foramen magnum margin. The alae deflect posteriorly and they gradually expand to the cartilaginous extreme. The neopalatines are curved bones, concave posteriorly. One-third of it inner length overlaps with the sphenethmoid. The outer edge reaches the pars palatine of the maxilla. The vomers are paired bones that overlap the sphenethmoid. Each vomer comprises a dentigerous process with a transverse and concave row that bears 4 to 5 teeth. The posterior margin forms the posterior margin of choanae. The maxillary arcade is complete. The upper jaw is composed of the premaxillae, maxillae and quadratojugal bones. Each premaxilla bears 4–5 teeth. The alary process is subrectangular, oriented dorsally curved backwards and not reach the nasals. The pars palatina is subrectangular and the palatine process is pointed. The maxilla is well-developed, pars fascialis is wide and pars palatina narrow. The teeth (19–24) are conical.
Suspensorium: Each pterygoid has well-developed the anterior, medial and posterior rami. The anterior ramus is expanded anteriorly, articulating with the inner side of the maxilla. The medial ramus does not reach the allae of parasphenoid, but it contacts on the prootic. The posterior ramus invests the cartilaginous quadrate process medially and terminates posteriorly at the angle of the jaw. The zygomatic ramus of the squamosal is slightly curved ( Fig. 6C View FIGURE 6 ). The otic ramus is expanded and shorter than zygomatic ramus. The ventral ramus is straight and the angle with the maxilla is about 45º. The annulus tympanic is oned dorsally, cartilaginous and joined to the zygomatic ramus. The coronoid process of the mandible is trapezoidal and normally developed. Columella presents.
Hyoid apparatus: The hyoid plate is cartilaginous and mineralized at posteromedial processes ( Fig. 6E View FIGURE 6 ). At midline the hyoid corpus is 1.2 times wider than long; the hypoglossal sinus is broad and U-shaped, approximately as deep as wide and its margins are parallel. The allary processes are thin, perpendicular to the axial axis of the hyoid plate, slightly oriented forward and with a distal expansion. The hyales are thin and curved; the anterior lateral processes are developed and slightly curved laterally. The postero-lateral processes are thin and oriented postero-laterally, their tips are sharp. The posterior ends of the posteromedial processes are cartilaginous and slightly expanded.
Pectoral girdle: The pectoral girdle is arciferous, the omosternum is cartilaginous with an expanded distal end ( Fig. 6D View FIGURE 6 ). The anterior expansion is shorter than the cartilaginous sternum. The omosternum slightly expanded anteriorly and stick-like. The sternum is wide and its distal end is rounded. The procoracoid is present and extends to the level of the internal extreme of the clavicle, the clavicles do not touch each other. The prolongation of the procoracoid extends between the clavicle and the scapula. In ventral view, the right cartilaginous epicoracoid overlaps the left. The pectoral fenestra, whose inner margin is concave is 1.5 times wider than long. Each of these apertures is anteriorly bordered by the procoracoid cartilage, medially by the epicoraciod cartilage, and posteriolly by the coracoid. Each clavicule is concave anteriorly. The glenoid end of the clavicle is expanded dorsolaterally into a wedge-shaped process that articulates with the pars acromialis of the scapula. The clavicles do not reach the glenoid fossa. The scapula is rectangular in shape and 1.3 times the coracoid. The scapula is composed of two planes: pars acromialis concave and the pars glenoid concave posteriorly. The coracoid is subrectangular and the distal ends are distally expanded. The glenoid cavity is limited by the pars glenoidalis and coracoid. The outer edge of the supra scapular cartilage is cartilaginous. The cleitrum consists of an ossified thin and bifid lamina, the posterior ramus is shorter of the anterior ramus slightly expanded, as long as the scapula; the anterior border ossified as cleitrum; the posterior and lateral margins unmineralized.
Axial osteology: The vertebral columnae is composed of eight procoelus, non-imbricate, independent presacral vertebrae ( Fig.7A, B View FIGURE 7 ). Presacral I (atlas) wide, shallow cervical cotyles widely separated. The presacrals II–IV with low neural spines, presacrals V–VIII with neural spine absent. Relative lengths of transverse processes and sacrum: III = sacrum <IV<II<V–VII<VIII. Distal ends of presacral III slightly expanded; transverse processes of presacrals V–VIII acuminated. Presacral II oriented anteriorly, III–VII oriented posteriorly and VIII oriented perpendicularly to the longitudinal axis. Sacral diapophysis rounded, end slightly expanded, oriented posterolateraly; sacrum with bicondylar articulation with urostyle. Urostyle robust bearing dorsal crest that is more developed anteriorly, approximately 1.2 times larger than sacrum plus presacral vertebral column. Overall length of pelvic girdle 1.6 times the length of sacrum plus presacral vertebral column. Ilial shaft poorly developed, interilial profile U-shaped, width of the U at the anterior ends of the ilia approximately 2.5 times its base. Ilium forming anterior margin of round acetabulum; preacetabulum forming approximately a 45º angle to the ilial shaft; ilia articulating with one another medially forming the anterior margin of acetabulum; ventral margin of acetabulum formed by cartilaginous pubis. The ischium is prominent, articulating with the ilium and fused with the pubis ( Fig. 7C View FIGURE 7 ).
Forelimb: Humerus as long and robust as the radioulna; phalangeal formula for manus 2-2-3-3; terminal phalanges pointed, distal carpals 2–4 fused; distal carpal 1, element Y, radiale and ulnare independent; prepollex with two elements (pattern C; Fabrezi 2001), the proximal triangular in shape and ossified; the distal element cartilaginous ( Fig.7D View FIGURE 7 ).
Hind limb: Femur and tibiofibula similar in length; tibiale and fibulare fused at the ends. Tarsal elements ossified; metatarsal IV and V articulate with the end of fibulare; metatarsal III articulates with tarsal 2–3, and metatarsal II articulates with the element Y; the metatarsal I articulate with tarsal 1. Phalangeal formula of the foot: 2-2-3-4-3, terminal phalanges pointed. The prehallux has two elements; proximal one ossified and smaller than the cartilaginous distal element ( Fig. 7E View FIGURE 7 ).
Tadpole. The tadpoles of E. altor are endotrophic and its description is based on five specimens collected at the type locality (one in stage 33 and four in stage 34). The total length ranges between 18.4–19.6 mm. Larva type IV ( Orton 1953) with elliptical body in dorsal view, slightly depressed ( Fig. 8A, B View FIGURE 8 ). Snout slightly truncated in lateral and dorsal profiles. Pupils are circular. The small nostrils are oval in shape, not protruding. The narial opening situated anterolaterally nearer to the snout than the anterior border of the eyes. The internarial distance 0.6 times the interorbital distance. The oral disc is ventral (sensu Mijares-Urrutia 1998), nearly circular in shape ( Fig. 8C View FIGURE 8 ). The margin of the oral disc slightly emarginated with a single row of the marginal papillae. Rostral gap 0.75 times the oral disc; mental gap absent. Intramarginal papillae absent. Upper and lower jaw sheaths well keratinized and with serrations. Labial tooth formula 2(2)/2. Tube spiracular short, reduced and sinistrally disposed; its aperture corresponds 0.5 times the eye diameter. Intestinal convolutions poorly defined and with abundant vitellum. Vent medial, large (0.22 times the body length), tubular in shape with its posterior extreme slightly sharpened, the aperture is longitudinal ( Fig. 8D View FIGURE 8 ). The caudal fins are low. Tail length 0.70 times the total length. Tail height low (0.85 times the body height). Tail width, 1.5 times the internarial distance. Tail axis curved dorsoventrally with myomeres well developed. Tip of the tail rounded. Body and tail unpigmented. The measurements of the tadpoles are shown in Table 3.
Chromosomes. The diploid number is 2n=30 and the Fundamental Number (NF) is 44. Calculation of arm ratios identifies pairs 1, 5, 9, 10 and 11 as metacentric (m), pairs 2 and 3 submetacentric (sm), and pairs 4, 6–8, 12– 15 as telocentric ( Table 4; Fig. 9 View FIGURE 9 ).
Pair
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Relative length ¹ 165 109 93 66 64 63 61 59 58 56 48 46 37 35 35
r ² 1.2 2.7 3.4 oe 1.3 oe 1.1 oe 1.1 oe 1.1 oe
Type ³ m sm* st t m t t t m m m t t t t
¹ According to Bogart 1970
² r = large arm/short arm
³m = metacentric, sm = submetacentric, st = subtelocentric, t = telocentric
Reproductive mode. Nests (N =30) and tadpoles were observed between May and August between the forest and meadowlands. The terrestrial eggs were easy to separate as in E. roseus ( Formas &Vera 1980) . Eggs (17–30, 5.5–5.7 mm in diameter) and tadpoles were grouped in moist burrows in the ground covered by logs or stones. In all cases the tadpoles were found away from any aquatic environment. A male was always observed near the tadpoles.
The eggs develop into endotrophic tadpoles that completing their total development within the nest. This particular reproductive mode, including terrestrial tadpoles, is an additional argument that support the hypothesis that E. altor is an independent lineage of E. roseus .
Distribution and natural history. At present, specimens of E. altor are known from the type locality and three additional sites [Alepue (39º36’S; 73º14’W), Chan-Chán (39º33’S; 73º12’W) and Curiñanco (39º39’S; 73º18’W)] located the western slopes of the Coastal range, between the mouth of the rivers Lingue (39º26’S; 73º12’W) and Valdivia (39º52’S; 73º23’W), Valdivia province. This area is covered by the typical vegetation of Valdivian rain forest ( Veblen 2007) where the following plants were identified: Drymis winteri , Laurelia phyllipiana , Weinmannia trichosperma , Dendroligotrichum dendroides , and Cladonia spp. There, the most common frogs are: Alsodes norae , Batrachyla antartandica , Batrachyla leptopus , Eupsophus vertebralis , Pleurodema thaul , and Rhinoderma darwinii . During January and February (austral summer) specimens of the small lizards Liolaemus pictus and L. cyanogaster were observed. Throughout the year, adult specimens of E. altor were found under rotten trees and at night walking through the vegetation ground. Mating calls (maximum activity at night), males with nuptial pads and gravid females were observed throughout May and August (austral winter). The clutches and tadpoles were always observed during May and June, and tadpoles between May and October in terrestrial nests, under logs or tree holes until 1 m above the ground ( Fig 5B, C, D View FIGURE 5 ).
Etymology. The specific name altor is derived from the Latin meaning “one who looks after or brings up its offspring”. This epithet is given in the masculine form of the word (the female form is altex) because we observed that in this species males are the care givers for offspring.
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